Edition 14 - Consider the role of lidocaine in our critical canine patients

Consider the role of lidocaine in our critical canine patients

In this edition we look at the use of lidocaine infusions in canine GDV. These two papers share difference perspectives and we encourage you to question the findings of each.

Evaluation of lidocaine treatment on frequency of cardiac arrhythmias, acute kidney injury, and hospitalization time in dogs with gastric dilatation volvulus. J Vet Emerg Crit Care (2012)

Objective: To determine whether early intravenous lidocaine administration reduces complications and improves outcomes in dogs with gastric dilatation-volvulus (GDV). 

Study Design

• Prospective study of 83 dogs with GDV treated with lidocaine.

• Compared with 47 historical control dogs that did not receive lidocaine.

• Opioid – pethidine 4mg/kg IM q4-6hrs

• Lidocaine protocol:

  • 2 mg/kg IV bolus immediately upon diagnosis

  • Followed by CRI 0.05 mg/kg/min for 24 hours (50mcg/kg/min)

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Key Findings

Outcome	Lidocaine Group (n=83)	Control Group (n=47)	P value
Cardiac arrhythmias	12.1% (10/83)	38.3% (18/47)	<0.001
Acute kidney injury (AKI)	0% (0/83)	6.3% (3/47)	0.045
Median hospitalization time	48 h	72 h	0.05
Mortality	10.8% (9/83)	23.4% (11/47)	0.056

Main Conclusions

1. Reduced cardiac arrhythmias

Dogs receiving lidocaine had a markedly lower incidence of postoperative ventricular arrhythmias compared with controls (12% vs 38%). This was the most significant clinical benefit observed. 

Our view: ventricular arrhythmias can be tolerated, provided they do not impact blood pressure. There does seem to be a clinical benefit here when you view this result in combination with the shorter hospitalisation – it’s unlikely that a dog would be discharged whilst still experiencing cardiac arrhythmias.

2. Reduced acute kidney injury

No dogs in the lidocaine group developed AKI, whereas 3 control dogs did. The authors suggest lidocaine's anti-inflammatory and vasodilatory effects may improve renal perfusion during reperfusion injury.

Our view: encouraging results, but more numbers needed to show that this is a real effect. We should ensure our fluid and vasopressor management are optimised in these cases.  

3. Shorter hospitalization

Median hospitalization was reduced from 72 hours to 48 hours, suggesting faster recovery and potentially lower treatment costs.

Our view: this is a great example of Enhanced Recovery After Surgery.

4. Trend toward lower mortality

Mortality was almost halved (10.8% vs 23.4%), but this difference did not reach statistical significance (P = 0.056). The study may have been underpowered to detect a mortality benefit. 

Our view: it would be great to see this work continued with larger numbers.

Adverse effects:

No clinically significant adverse effects attributable to lidocaine were observed in the treated dogs. The study didn’t specifically aim to characterise AEs so perhaps this explains this result.

Clinical Relevance

The authors propose that early lidocaine administration before gastric decompression and fluid resuscitation may attenuate ischemia-reperfusion injury, thereby reducing postoperative complications associated with GDV. 

Our view: we agree that there appears to be a clinical benefit to this approach, although of course will say that due to numbers, further work is required.  

Limitations

• Non-randomized study.

• Historical rather than concurrent controls.

• Not blinded or placebo controlled.

• Improvements in GDV management over time may have influenced outcomes.

• Sample size may have been insufficient to demonstrate a statistically significant mortality benefit. 

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Bottom Line

In dogs with GDV, early IV lidocaine (2 mg/kg bolus followed by CRI 0.05 mg/kg/min for 24 hr) was associated with:

• Significantly fewer cardiac arrhythmias.

• Significantly less AKI.

• Shorter hospitalization.

• A strong trend toward improved survival.

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The study supports the use of lidocaine as part of GDV stabilization, but larger randomized controlled trials are needed to confirm these benefits. 

The question this work raises is what produces this effect? Is it arrhythmia prevention from sodium channel blockade or something else? This next study examined the role of inflammatory mediators in GDV.  

Inflammatory biomarker concentrations in dogs with gastric dilatation volvulus with and without 24 hr intravenous lidocaine.

Objective

To determine whether intravenous lidocaine has measurable anti-inflammatory effects in dogs with gastric dilatation-volvulus (GDV) by comparing inflammatory biomarkers in dogs receiving lidocaine versus those not receiving lidocaine. A secondary aim was to evaluate potential adverse effects of lidocaine. 

Study Design

• Prospective, randomized, non-blinded cohort study.

• 35 client-owned dogs with GDV:

  • 20 dogs: lidocaine group (LIDO)

  • 15 dogs: no lidocaine group (NO-LIDO)

• Lidocaine protocol:

  • 2 mg/kg IV over 15 minutes before treatment.

  • CRI of 50 μg/kg/min for 24 hours.

• Opioid – methadone 0.2mg/kg or fentanyl plus fentanyl CRI 5ug/kg/hr for 24hrs

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Biomarkers Assessed

Measured at admission, immediately after surgery, 24 hours, and 48 hours post-surgery:

• IL-6, IL-7, IL-8, IL-10, IL-15, IL-18, IFN-γ, MCP-1, KC-like

• C-reactive protein (CRP)

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Key Findings

1. No significant effect on cytokines

Lidocaine did not significantly reduce plasma concentrations of inflammatory cytokines compared with controls at any sampling point. 

2. Lower CRP concentrations

Dogs receiving lidocaine had significantly lower CRP concentrations:

• 24 hr: 97.5 vs 127.9 mg/L-equivalent values reported by authors (p = 0.046)

• 48 hr: 73.7 vs 116.3 (p = 0.002) 

This suggests a possible anti-inflammatory effect despite the lack of cytokine differences. 

3. Mortality

• Overall mortality: 20%

• No significant difference in survival between groups. 

4. Cardiac arrhythmias

The study was unable to demonstrate a statistically significant anti-arrhythmic benefit, largely because the overall incidence of ventricular arrhythmias was low. However, three dogs initially assigned to the non-lidocaine group required rescue lidocaine therapy due to clinically important arrhythmias. 

Adverse Effects

Compared with controls, dogs receiving lidocaine showed:

Finding	Result
Mentation	More depressed/dull
Appetite	Longer anorexia
Temperature	Lower at 24 h
Hospitalization	Longer stay
Urination problems	More common (not statistically significant)

Median duration of anorexia:

• Lidocaine: 45 hr

• No lidocaine: 19 hr (p = 0.044)

Median hospitalization:

• Lidocaine: 2.9 days

• No lidocaine: 2.5 days (p = 0.015) 

Our view: is this really significant clinically?

Prognostic Biomarker Finding

Dogs that died had significantly higher admission IL-6 concentrations than survivors, suggesting IL-6 may have prognostic value in GDV. 

Comparison with the 2012 Bruchim Study

Outcome	Bruchim 2012	Brunner 2024
Cardiac arrhythmias	Significantly reduced with lidocaine	Not proven
AKI	Reduced with lidocaine	Separate renal biomarker study found no renoprotective evidence
Hospitalization	Shorter with lidocaine	Longer with lidocaine (clinical significance)
Inflammatory cytokines	Not measured	No significant reduction
CRP	Not measured	Lower with lidocaine
Side effects	No major adverse effects reported	Sedation, anorexia, prolonged hospitalization observed

Clinical Take-Home Message

This more recent randomized study questions some of the broader benefits previously attributed to lidocaine in GDV. While lidocaine was associated with lower CRP concentrations, it did not significantly reduce cytokine concentrations, improve survival, or clearly demonstrate organ-protective effects. Furthermore, treated dogs experienced more depression, prolonged anorexia, and longer hospital stays. The authors conclude that the potential benefits of lidocaine should be carefully weighed against these adverse effects when managing dogs with GDV. 

What’s missing and what other advantages could there be to lidocaine in these cases?

Consider this question and then scroll to after the references for our thoughts.

References

Bruchim Y, Itay S, Shira BH, Kelmer E, Sigal Y, Itamar A, Gilad S. Evaluation of lidocaine treatment on frequency of cardiac arrhythmias, acute kidney injury, and hospitalization time in dogs with gastric dilatation volvulus. J Vet Emerg Crit Care (San Antonio). 2012 Aug;22(4):419-27. doi: 10.1111/j.1476-4431.2012.00779.x.

Brunner A, Lehmann A, Hettlich B, Peters LM, Doras CJ, Adamik KN. Inflammatory biomarker concentrations in dogs with gastric dilatation volvulus with and without 24-h intravenous lidocaine. Front Vet Sci. 2024 Jan 4;10:1287844. doi: 10.3389/fvets.2023.1287844.

Our thoughts

·      Lidocaine can have a MAC sparing effect and this could impact blood pressure.

·      Lidocaine has an opioid sparing effect and enables us to reduce the dose or frequency of opioids – and thus reduce their adverse effects.

·      Maropitant can be used to manage the nausea with lidocaine and that could offer a mitigation against this.

·      Post-operative pain scores were not presented in either study. Our view is that lidocaine provides an analgesic benefit – dogs receiving lidocaine are much more comfortable on abdominal palpation.